94 taurus gl overheating

The other day i was driving my taurus gl 3.0l and i noticed the air conditioner start to get warm. After a few minutes i also noticed the temperature slowly climing so i pulled off the road just before it got to the red. I noticed water bubbling in the plastic tank and some bubbled out. After it cooled down i was able to drive it home ok. My dad and i figured that it was the thermostat so i took that out and it was in 3 pieces, i replaced that and drove the car around the block a few times to warm the engine up and noticed that i was having the same problem. To me it seems as if there isn't any water flow. Besides the thermostat what could cause this? im stumped.

Was the thermostat really in three pieces, or where some pieces of the water pump impeller stuck in the thermostat? It's not all that uncommon for the water pump impellers to fail on the Taurus. Try the "Search this forum" feature from the Taurus forum main page to get more details on failure modes and affected model years.

Also, verify that the radiator cooling fan was turning on. I'm betting that it's not coming on either as that would contribute to the condensor not having enough air flowing over it which could be why the A/C started blowing warm.

-Rod

ya its not the impeller, it was actually in 3 pieces. but you were definately right about the fan, i ran the car until it was past normal heat and the fan never turned on. so now the next question is what might be wrong with the fan? do you have any ideas?

You'll need to determine if the fan is not running because the fan motor is faulty, the relay for the fan is not working properly (integrated into the Constant Control Relay Module - CCRM), or if the signal to the CCRM is not there. The signal to the CCRM for cooling fan is driven by the PCM which gets its information from the Coolant Temperature Sensor (not switch).

Verify the fuse is good for the radiator fan. Try turning on the A/C to see if the fan kicks in with A/C. If it does not, they you can shut the engine off, pull the fan connector, securely insert voltmeter probes, start the engine with the A/C on again and see if voltage is present. If it is, then either the fan is faulty or there is a corroded/loose connection that isn't allowing enough current to the fan motor. You could try backprobing the fan connector and plugging in the fan to determine this, full battery voltage, or close to it, and the motor is most likely the problem.

-Rod

I'm surprised Rod didn't mention to do this, but the temperature sensor he mentioned is on top of the thermastat housing, with the two wire connector right on top of it. With the engine on and the sensor disconnected, the fan should come right on if everything else is working as it should.. As Rod said, the ac will turn the fan on too. If you have established that the fan system works, except when the wiring is connected to the temp sensor with a hot engine, then the sensor is probably not good. You can do a resistance test on it. At 65 deg F, it's ~40,500 ohms, then when engine gets hot, ~180 to ~220 deg F it's ~3800 to ~1800 ohms. Close is ok. Don't buy a plastic sensor if needed. Only brass. There have been problems with the plastic one.

ok so there wasn't a sensor directly above the thermostat housing but i think the wire in this picture is it. it seems to be going into the heater core.

http://i73.photobucket.com/albums/i224/fuckass6771/P1060892.jpg

Sorry, my bad. I should have checked better on this as I'm so used to doing everything on the 3.8 engine. What you have found is the Coolant Temperature Sending Unit. Didn't you say it has one wire? It would be Red/White. That and your location photo confirm you have the sending unit for the temp gauge in the instrument cluster. The ECT is a two wire sensor located in front of the distributor and behind the ignition coil and the valve cover oil fill. I suspect it is screwed into the intake manifold. The wires to it are Light Green/Red and Gray/Red.

Hope this helps.